Experience has shown that it is costly and time-consuming to let the staff collect service carts that have been used. For this reason, the practice has been introduced in many places of making a service cart available solely upon payment of a deposit, being refunded when the cart is returned. This practice is, however, by the users often experienced as a rather complicated course of action. Systems comprising both electronic monitoring and payment of a deposit are known from the International Patent Applications No. WO 84104660 and No. WO 97/11441.
WO 84/04660 discloses a system, in which the electronic monitoring serves to ascertain whether a service cart belongs to a predetermined collection station, after which a deposit has to be paid in order to get the service cart free for use in an activity area.
U.S. Pat. No. 5,119,087 discloses a deposit free system in which each cart is provided with a target, while a sensor detects the return of a shopping cart to a cart-returning station. According to a counter system, aprize is awarded to the person returning the shopping cart to the returning station.
WO 97/11441 discloses a system specially adapted for lending and re-parking of service carts from different shops. The system is based upon the payment of a refund of at least part of a lending deposit when the cart is returned.